An ultrasound apparatus is an apparatus that transmits an ultrasonic signal and, if the ultrasonic signal is reflected from an object, images a structure and a characteristic of the object by using information included in the reflected ultrasonic signal. There is a growing tendency to use the ultrasound apparatus with a noninvasive characteristic of the ultrasound apparatus, and thus there is a need for providing a high-quality image.
A transducer of the ultrasound apparatus that transmits an ultrasonic signal is roughly classified into a straight line type of linear transducer and a curved type of convex transducer.
If a plane wave is transmitted by using the linear transducer, the same number of scanning lines may be maintained per area all over a region to be imaged, and thus an image having a uniform resolution may be acquired. However, the region to be imaged by the linear transducer is relatively smaller than when using the convex transducer that will be described later and thus is inconvenient in terms of use and is difficult to be applied in some clinical application fields. In other words, if a plane wave is used, an image having a uniform resolution may be acquired, but a region to be imaged is relatively small.
If the convex transducer is used, an ultrasonic wave is transmitted in a radial form according to a curved shape of the convex transducer so as to acquire a relatively wider region to be imaged than when using the linear transducer. However, since the convex transducer uses a radial scanning method, the number of scanning lines per area is smaller as being far away from the convex transducer. As a result, a non-uniform image whose resolution is deteriorated and whose speckles become larger is provided.
Therefore, there is a need to secure a wide region, which has a uniform resolution and is to be imaged, by using a plane wave.